A new study shows that octopuses cycle between active and quiet sleep states in a way similar to humans, CBC reports. Since octopuses are known for their high learning capacity and complex nervous systems, neuroscientist Sidarta Ribeiro wanted to see if their brains required multiple sleep states. “The animals had so many changes in the colours of the skin, and the texture,” Ribeiro told Quirks & Quarks host Bob McDonald. “The eyes moved around a lot. The arms moved a little bit in circles, and they also moved all their tentacles…. It is tempting to speculate that when they are quiet and doing the half-and-half pattern, maybe they are dreaming about one of those events like a courtship event.”
